Older blog entries for fzort (starting at number 40)

Back in the zone

After a couple of months with no serious coding (not counting what I've been doing for work, of course), it's good to be back. More info on the project I've been working on in the next few days.

Chess

While searching for ways to improve my playing, I recently discovered chess problems. The stuff is more addictive than Sudoku. Here is a nice collection of easy ones, for beginners like me.

My playing still sucks, though.

Read Wilson's Spin in one sitting last Saturday. It's that good.

mattdo: there's no need to let go of your hard-earned vi chops. Use emacs viper-mode and be happy.

Add this to your .emacs file:

  (setq viper-mode t)
  (setq viper-inhibit-startup-message 't)
  (setq viper-expert-level '3)
  (require 'viper)

... and voila, vi key bindings! You'll still have to learn C-c C-x and a few other combinations to deal with things like buffers and windows, though, but they're easy to get used to. Try :help for more info. Better yet: find the manual (viper.dvi) and, if possible, print it out.

On other news: updated my personal page. Some local headlines are making me crankier than usual.

Happy birthday to me

Bought myself The Little Schemer. My wife says it's the cutest thing ever.

On a somewhat related note

... hacked together some lazy streams. In C++. Here it is. It looks ghastly.

DAMN, I RULE

I can finally brag about it, now that the winning entries seem to be out at last: my code was awarded 'Best of Show' at the 18th IOCCC.

You can get the tarball with all the winning entries at the contest site, but here's mine, and the original remarks file, borked grammar and all. Compile with -lm.

haruspex, bi: thank you. Here is, ahem, more of the same. I'll try to add some colors this weekend.

Stumbled upon some SIGSEGV problems when trying to run UMB Scheme 3.2 here at work. UMB Scheme is the interpreter I've been using at home, on my hopelessly obsolete Linux distribution. Had a look at the source code. The bug was a bit puzzling at first - the code seemed to work perfectly under valgrind! Turned out the author was using the sign of a pointer as a sort of flag; when it's negative, flip the sign and follow the resulting pointer somewhere else. Evil! At least on the system where I'm at, addresses of stack allocated and heap allocated objects have different signs. I did the obvious thing; here's a patch that fixes the problem.

Why even bother with UMB Scheme? Well, newer Scheme interpreters are a bit picky about the argument for force being a promise. This prevented me from running, on newer interpreters, this breathtakingly beautiful piece of code. Well, yes, I only found out about lazy streams yesterday; this stuff still looks to me a bit like magic.

Edit: redi, yes, that's it. Thanks.

I've been toying a bit with non photorealistic rendering. Some results are here and here, and some hackish C code is here. It uses this algorithm to draw lines.

Oh, and I think I finally got call-with-current-continuation. Yay.

The wizards at the Ivory Tower seem to be fond of functional programming, so I decided to teach myself Scheme to see first hand what the hoopla is about. Thought that a good way to practice would be to try my hand at writing scripts for Gimp. This is my first script, and this is how the output looks like.

Hacking

Hacked vlock to display some ASCII animations on the background, instead of just a boring password prompt. Sent the changes to the author, but the e-mail bounced. :/ (Michael K. Johnson, are you out there?)

Get the modified version here. For now it displays just two animations, some spinning stars and a maze solver (which one to show is picked randomly). Not sure if placing a modified version of GPL code on my site is against the license or something.

advogato

Could this be a symptom of a bug in the trust metric?